Haller is at the edge of Gimheldt's inner life zone and just barely supports life. Haller has a solid iron core with just enough density to sustain a thin atmosphere of mostly nitrogen, with oxygen, carbon dioxide, argon and other trace gases. During the day, the sky appears a deep purple. However, the low oxygen levels makes Haller extremely vulnerable to Gimheldt's radiation making it a poor candidate for terraformation.

The thin atmosphere and small size of the planet make temperatures extremely variable ranging anywhere from an unbearable 180° F to a chilly -100° F.

Most of Haller's crust is composed of sandstone, but its core is made of solid iron, making it an extremely valuable planet to mine. However, there is a relative lack of volcanic activity. The most predominant autotrophic life are lichens colored purple to protect against Gimheldt's radiation. These lichens reproduce via spore stalks, and are referred to as Purple Grass. The planet's fauna mostly consists of microbes that metabolize iron, excreting acid to break it down.

Haller only contains 5% surface water, but most of the planet's water is locked away within an underground layer of water-ice. Much of the surface has been oxidized, making the ground appear shades of red and brown. Purple Grass sparsely covers the planet in large pockets of patches which are right above subsurface lakes created from the water-ice layer locked beneath Haller's rocky crust that melted away . Aside from these Purple Grass patches, most of the planet is barren.

Haller has plenty of large impact craters. As there are no planets large enough to perturb comets beyond Haller's orbit, meteors are a common sight. One of the most aesthetic yet dangerous qualities of the planet are the brilliant meteor showers that regularly rain down on the planet due to gravitational displacement of debris. These meteors contained organic molecules and water allowing life to arise on Haller.